Method and system for reducing backhaul utilization during base station handoff in wireless networks

ABSTRACT

Systems and methods are provided that facilitate active queue management of internet-protocol data packets generated in a data packet switched wireless network. Queue management can be effected in a serving base station as well as in an access terminal, and the application that generates the data packets can be executed locally or remotely to either the base station or access terminal. Management of the generated data packets is effected via a marking/dropping of data packets according to an adaptive response function that can be deterministic or stochastic, and can depend of multiple communication generalized indicators, which include packet queue size, queue delay, channel conditions, frequency reuse, operation bandwidth, and bandwidth-delay product. Historical data related to the communication generalized indicators can be employed to determine response functions via thresholds and rates for marking/dropping data packets.

CLAIM OF PRIORITY UNDER 35 U.S.C. §119

This application for patent claims the benefit of U.S. ProvisionalApplication Ser. No. 60/868,711 filed on Dec. 5, 2006, and entitled“METHOD AND SYSTEM FOR REDUCING BACKHAUL UTILIZATION DIRING BASE STATIONHANDOFF IN WIRELESS NETWORKS.” The entirety of this application isexpressly incorporated herein by reference.

BACKGROUND

1. Field

The subject disclosure relates generally to wireless communication andmore particularly to base station handoff in wireless communicationsystems.

2. Background

Wireless communication systems have become a prevalent means by which amajority of people worldwide have come to communicate. Wirelesscommunication devices have become smaller and more powerful in order tomeet consumer needs and to improve portability and convenience. Theincrease in processing power in mobile devices such as cellulartelephones has lead to an increase in demands on wireless networktransmission systems. Such systems typically are not as easily updatedas the cellular devices that communicate there over. As mobile devicecapabilities expand, it can be difficult to maintain an older wirelessnetwork system in a manner that facilitates fully exploiting new andimproved wireless device capabilities.

Wireless communication systems generally utilize different approaches togenerate transmission resources in the form of channels. These systemsmay be code division multiplexing (CDM) systems, frequency divisionmultiplexing (FDM) systems, and time division multiplexing (TDM)systems. One commonly utilized variant of FDM is orthogonal frequencydivision multiplexing (OFDM) that effectively partitions the overallsystem bandwidth into multiple orthogonal subcarriers. These subcarriersmay also be referred to as tones, bins, and frequency channels. Eachsubcarrier can be modulated with data. With time division basedtechniques, each subcarrier can comprise a portion of sequential timeslices or time slots. Each user may be provided with one or more timeslot and subcarrier combinations for transmitting and receivinginformation in a defined burst period or frame. The hopping schemes maygenerally be a symbol rate hopping scheme or a block hopping scheme.

Code division based techniques typically transmit data over a number offrequencies available at any time in a range. In general, data isdigitized and spread over available bandwidth, wherein multiple userscan be overlaid on the channel and respective users can be assigned aunique sequence code. Users can transmit in the same wide-band chunk ofspectrum, wherein each user's signal is spread over the entire bandwidthby its respective unique spreading code. This technique can provide forsharing, wherein one or more users can concurrently transmit andreceive. Such sharing can be achieved through spread spectrum digitalmodulation, wherein a user's stream of bits is encoded and spread acrossa very wide channel in a pseudo-random fashion. The receiver is designedto recognize the associated unique sequence code and undo therandomization in order to collect the bits for a particular user in acoherent manner.

Independently of the technique employed to accomplish a wirelesscommunication, in certain wireless networks the amount of data thatneeds to be transferred between base stations during a handoff event maybe large due to a large amount of data buffered at a base station whenhandoff is necessary. One important cause is the absence of tight flowcontrol between the access gateway and the base station. Such asubstantial data transfer can significantly increase bandwidthrequirement at a base station. Proprietary solutions are expensive andhardly transferable. Therefore there is a need in the art for systemsand methods that facilitate effective base station handoff in a wirelesscommunication network.

SUMMARY

The following presents a simplified summary in order to provide a basicunderstanding of some aspects of the disclosed embodiments. This summaryis not an extensive overview and is intended to neither identify key orcritical elements nor delineate the scope of such embodiments. Itspurpose is to present some concepts of the described embodiments in asimplified form as a prelude to the more detailed description that ispresented later.

In an aspect, the subject description discloses a wireless communicationdevice comprising: a processor configured to receive a set ofinternet-protocol (IP) data packets generated by a computer-implementedapplication, wherein the computer implemented application executesremotely; to assign a data packet queue to the received set of IP datapackets; to mark or drop a subset of the IP data packets in the receivedset of IP data packets based at least in part on an adaptivecommunication generalized indicator; to convey a complementary set of IPdata packets associated with the application and extant in the datapacket application queue; and a memory coupled to the at least oneprocessor.

In another aspect, a method employed in a wireless communicationenvironment is described, the method comprising: receiving aninternet-protocol (IP) data packet associated with acomputer-implemented application; buffering the IP data packet; markingor dropping the IP data packet based at least in part on an adaptiveresponse function, wherein the response function depends on a set ofcommunication generalized indicators; and conveying a marked IP datapacket.

In yet another aspect, the subject specification describes a computerprogram product comprising a computer-readable medium including: codefor causing at least one computer to receive an internet-protocol (IP)data packet associated with a computer implemented application; code forcausing at least one computer to buffer the IP data packet; code forcausing at least one computer to mark or drop the IP data packet basedat least in part on an adaptive response function; and code for causingat least one computer to convey a marked IP data packet.

In a yet further aspect, an apparatus that operates in a wireless systemis disclosed, the apparatus comprising: means for receiving a set ofinternet-protocol (IP) data packets associated with acomputer-implemented application executing remotely; means for assigninga data packet queue to the received set of IP data packets; means formarking or dropping a subset of the IP data packets in the received setof IP data packets based at least in part on an adaptive communicationgeneralized indicator and an associated threshold thereof, means forreceiving the adaptive communication generalized indicator and theassociated threshold thereof, and means for conveying a complementaryset of IP data packets associated with the application and extant in thedata packet application queue.

In another aspect, the subject specification describes a wirelesscommunication device comprising: a processor configured to receive aninternet-protocol (IP) data packet generated by a computer-implementedapplication, wherein the computer implemented application executesremotely; to mark the received IP data packet based at least in part ona response function; to convey the received IP data packet; and toconvey a marking indicator; and a memory coupled to the processor.

In yet another aspect, a method utilized in a wireless communicationsystem is disclosed, the method comprising: receiving aninternet-protocol (IP) data packet generated by a computer-implementedapplication, wherein the computer implemented application executesremotely; marking or dropping the received IP data packet based at leastin part on a response function that depends on a communicationgeneralized indicator; and conveying a marking indicator.

In a further aspect, an apparatus that operates in a wirelessenvironment is described herein, the apparatus comprising: means forreceiving an internet-protocol (IP) data packet generated by acomputer-implemented application; means for buffering the received IPdata packet; means for marking or dropping the received IP data packetaccording to a deterministic or stochastic response function; and meansfor conveying a marked IP data packet.

In a still further aspect, the subject description discloses a computerprogram product including a computer-readable medium comprising: codefor causing at least one computer to receive an internet-protocol (IP)data packet generated by a first computer-implemented application; codefor causing at least one computer to generate a set of IP data packetsassociated with a second computer-implemented application; code forcausing at least one computer to mark or drop the received IP datapacket or at least one of the generated IP data packets based at leastin part on a response function that depends on a communicationgeneralized indicator; code for causing at least one computer to conveya marking indicator; and code for causing at least one computer toconvey at least one of the IP data packets in the set of generated IPdata packets.

To the accomplishment of the foregoing and related ends, one or moreembodiments comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative aspectsand are indicative of but a few of the various ways in which theprinciples of the embodiments may be employed. Other advantages andnovel features will become apparent from the following detaileddescription when considered in conjunction with the drawings and thedisclosed embodiments are intended to include all such aspects and theirequivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example wireless multiple-access communicationsystem in accordance with various aspects set forth herein.

FIGS. 2A, 2B, and 2C illustrate block diagrams of example systems thatfacilitate queue management during communication according to aspectsdescribed herein.

FIGS. 3A, 3B, and 3C are schematic diagrams that illustrate,respectively, a set of example application queues that can be activelymanaged and packet marking/dropping according to a predeterminedadaptive response function, e.g., a deterministic function or,alternatively, a marking/dropping probability function; and examples ofsaid adaptive response functions.

FIG. 4 is a block diagram of an example base station that comprises anexample queue management component that manages incoming IP data packetsaccording to an aspect disclosed herein.

FIG. 5 is a block diagram of an example system that facilitates relayingIP data packet(s) among base stations prior to handoff.

FIG. 6 illustrates a block diagram of an example system that facilitatesqueue management based on reconfiguration of the operation of an accessterminal according to an aspect disclosed herein.

FIG. 7 is a block diagram of an example embodiment of a transmittersystem and a receiver system in MIMO operation.

FIG. 8 illustrates a block diagram of an example MU-MIMO system.

FIG. 9 presents a flowchart to a method for managing a data queue in abase station that operates in a wireless distributed network andfacilitating base station handoff in accordance with an aspect.

FIG. 10 presents a flowchart to a method for managing a data queue in abase station that operates in a wireless distributed network andfacilitating base station handoff in accordance with an aspect.

FIG. 11 illustrates a block diagram of an example system that enablesmanaging a queue in a base station according to aspects describedherein.

FIG. 12 illustrates a block diagram of an example system that enablesmanaging a queue in an access terminal according to aspects describedherein.

DETAILED DESCRIPTION

Various embodiments are now described with reference to the drawings,wherein like reference numerals are used to refer to like elementsthroughout. In the following description, for purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of one or more embodiments. It may be evident, however,that such embodiment(s) may be practiced without these specific details.In other instances, well-known structures and devices are shown in blockdiagram form in order to facilitate describing one or more embodiments.

As used in this application, the terms “system,” “component,” “module,”“application,” and the like are intended to refer to a computer-relatedentity, either hardware, firmware, a combination of hardware andsoftware, software, or software in execution. For example, a componentmay be, but is not limited to being, a process running on a processor, aprocessor, an object, an executable, a thread of execution, a program,and/or a computer. By way of illustration, both an application runningon a computing device and the computing device can be a component. Oneor more components can reside within a process and/or thread ofexecution and a component may be localized on one computer and/ordistributed between two or more computers. In addition, these componentscan execute from various computer readable media having various datastructures stored thereon. The components may communicate by way oflocal and/or remote processes such as in accordance with a signal havingone or more data packets (e.g., data from one component interacting withanother component in a local system, distributed system, and/or across anetwork such as the Internet with other systems by way of the signal).

Moreover, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or”. That is, unless specified otherwise, or clearfrom context, “X employs A or B” is intended to mean any of the naturalinclusive permutations. That is, if X employs A; X employs B; or Xemploys both A and B, then “X employs A or B” is satisfied under any ofthe foregoing instances. In addition, the articles “a” and “an” as usedin this application and the appended claims should generally beconstrued to mean “one or more” unless specified otherwise or clear fromcontext to be directed to a singular form.

Various embodiments are described herein in connection with a wirelessterminal. A wireless terminal may refer to a device providing voiceand/or data connectivity to a user. A wireless terminal may be connectedto a computing device such as a laptop computer or desktop computer, orit may be a self contained device such as a personal digital assistant(PDA). A wireless terminal can also be called a system, a subscriberunit, a subscriber station, a mobile station, a mobile terminal, amobile, a remote station, an access point, a remote terminal, an accessterminal, a user terminal, a user agent, a user device, customerpremises equipment, or user equipment. A wireless terminal may be asubscriber station, wireless device, cellular telephone, PCS telephone,cordless telephone, a session initiation protocol (SIP) phone, awireless local loop (WLL) station, a personal digital assistant (PDA), ahandheld device having wireless connection capability, or otherprocessing device connected to a wireless modem.

A base station may refer to a device in an access network thatcommunicates over the air-interface, through one or more sectors, withwireless terminals, and with other base stations through backhaulnetwork communication. The base station may act as a router between thewireless terminal and the rest of the access network, which may includean IP network, by converting received air-interface frames to IPpackets. The base station also coordinates management of attributes forthe air interface. Moreover, various embodiments are described herein inconnection with a base station. A base station may be utilized forcommunicating with mobile device(s) and may also be referred to as anaccess point, Node B, evolved Node B (eNodeB), evolved base station(eBS), access network (AN) or some other terminology.

Referring now to the drawings, FIG. 1 is an illustration of a wirelessmultiple-access communication system 100 in accordance with variousaspects. In one example, the wireless multiple-access communicationsystem 100 includes multiple base stations 110 and multiple terminals120. Further, one or more base stations 110 can communicate with one ormore terminals 120. By way of non-limiting example, a base station 110can be an access point, a Node B, and/or another appropriate networkentity. Each base station 110 provides communication coverage for aparticular geographic area 102 a-c. As used herein and generally in theart, the term “cell” can refer to a base station 110 and/or its coveragearea 102 a-c depending on the context in which the term is used.

To improve system capacity, the coverage area 102 a, 102 b, or 102 ccorresponding to a base station 110 can be partitioned into multiplesmaller areas (e.g., areas 104 a, 104 b, and 104 c). Each of the smallerareas 104 a, 104 b, and 104 c can be served by a respective basetransceiver subsystem (BTS, not shown). As used herein and generally inthe art, the term “sector” can refer to a BTS and/or its coverage areadepending on the context in which the term is used. In one example,sectors 104 a, 104 b, 104 c in a cell 102 a, 102 b, 102 c can be formedby groups of antennas (not shown) at base station 110, where each groupof antennas is responsible for communication with terminals 120 in aportion of the cell 102 a, 102 b, or 102 c. For example, a base station110 serving cell 102 a can have a first antenna group corresponding tosector 104 a, a second antenna group corresponding to sector 104 b, anda third antenna group corresponding to sector 104 c. However, it shouldbe appreciated that the various aspects disclosed herein can be used ina system having sectorized and/or unsectorized cells. Further, it shouldbe appreciated that all suitable wireless communication networks havingany number of sectorized and/or unsectorized cells are intended to fallwithin the scope of the hereto appended claims. For simplicity, the term“base station” as used herein can refer both to a station that serves asector as well as a station that serves a cell. While the followingdescription generally relates to a system in which each terminalcommunicates with one serving access point for simplicity, it should beappreciated that terminals can communicate with any number of servingaccess points

In accordance with one aspect, terminals 120 can be dispersed throughoutthe system 100. Each terminal 120 can be stationary or mobile. By way ofnon-limiting example, a terminal 120 can be an access terminal (AT), amobile station, user equipment, a subscriber station, and/or anotherappropriate network entity. Further, a terminal 120 can communicate withany number of base stations 110 or no base stations 110 at any givenmoment.

In another example, the system 100 can utilize a centralizedarchitecture by employing a system controller 130 that can be coupled toone or more base stations 110 and provide coordination and control forthe base stations 110. In accordance with alternative aspects, systemcontroller 130 can be a single network entity or a collection of networkentities. Additionally, the system 100 can utilize a distributedarchitecture to allow the base stations 110 to communicate with eachother as needed. Backhaul network communication 135 can facilitatepoint-to-point communication between base stations employing such adistributed architecture. In one example, system controller 130 canadditionally contain one or more connections to multiple networks. Thesenetworks can include the Internet, other packet based networks, and/orcircuit switched voice networks that can provide information to and/orfrom terminals 120 in communication with one or more base stations 110in system 100. In another example, system controller 130 can include orbe coupled with a scheduler (not shown) that can schedule transmissionsto and/or from terminals 120. Alternatively, the scheduler can reside ineach individual cell 102, each sector 104, or a combination thereof.

In an example, system 100 can utilize one or more multiple-accessschemes, such as CDMA, TDMA, FDMA, OFDMA, Single-Carrier FDMA (SC-FDMA),and/or other suitable multiple-access schemes. TDMA utilizes timedivision multiplexing (TDM), wherein transmissions for differentterminals 120 are orthogonalized by transmitting in different timeintervals. FDMA utilizes frequency division multiplexing (FDM), whereintransmissions for different terminals 120 are orthogonalized bytransmitting in different frequency subcarriers. In one example, TDMAand FDMA systems can also use code division multiplexing (CDM), whereintransmissions for multiple terminals can be orthogonalized usingdifferent orthogonal codes (e.g., Walsh codes) even though they are sentin the same time interval or frequency sub-carrier. OFDMA utilizesOrthogonal Frequency Division Multiplexing (OFDM), and SC-FDMA utilizesSingle-Carrier Frequency Division Multiplexing (SC-FDM). OFDM and SC-FDMcan partition the system bandwidth into multiple orthogonal subcarriers(e.g., tones, bins, . . . ), each of which can be modulated with data.Typically, modulation symbols are sent in the frequency domain with OFDMand in the time domain with SC-FDM. Additionally and/or alternatively,the system bandwidth can be divided into one or more frequency carriers,each of which can contain one or more subcarriers. System 100 can alsoutilize a combination of multiple-access schemes, such as OFDMA andCDMA. While the power control techniques provided herein are generallydescribed for an OFDMA system, it should be appreciated that thetechniques described herein can similarly be applied to any wirelesscommunication system.

In another example, base stations 110 and terminals 120 in system 100can communicate data using one or more data channels and signaling usingone or more control channels. Data channels utilized by system 100 canbe assigned to active terminals 120 such that each data channel is usedby only one terminal at any given time. Alternatively, data channels canbe assigned to multiple terminals 120, which can be superimposed ororthogonally scheduled on a data channel. To conserve system resources,control channels utilized by system 100 can also be shared amongmultiple terminals 120 using, for example, code division multiplexing.In one example, data channels orthogonally multiplexed only in frequencyand time (e.g., data channels not multiplexed using CDM) can be lesssusceptible to loss in orthogonality due to channel conditions andreceiver imperfections than corresponding control channels.

FIG. 2A illustrates a block diagram of an example system 200 thatfacilitates queue management during communication among a base stationand an access terminal in a distributed, data-packet switched wirelessnetwork. A network node 210 generates data packet(s) through a packetgeneration component 214 which typically conveys information generatedby an application and employs an internet protocol (e.g., IPv4, IPv6, orIP mobility). A network node 210 can be a node in the internet or insubstantially any IP data-switched distributed network. IP datapacket(s) 229 can be conveyed via (low bandwidth) backhaul communication(e.g., link 135), typically through an access gateway (not shown), to abase station 230 which (i) manages a queue associated with theapplication that creates the IP data packets, (ii) routes IP datapacket(s) according to said active queue management, and (iii) schedulesand transmits the IP data packet(s) to an access terminal 250 over awireless forward link 245. As a result of the active queue management,base station 230 will modify one or more bits in the header of aconveyed IP data packet. When the IP data packet(s) 229 are received inaccess terminal 250, as part of an application (not shown), accessterminal 250 can echo the packet marking in a marking indicator 248associated with a response IP data packet(s). Marking indicator 248 canbe conveyed to the network node 210 in order to adjust a data packetgeneration rate in view of possible queue congestion—e.g., accumulationof IP data packet(s) in a buffer (see below). Alternatively, or inaddition, as a sign of queue congestion, IP packet(s) can be droppedinstead of marked; dropped packets can also result in an applicationreducing a packet generation rate. As a result of reducing the IP packetgeneration rate, the number of queued packets in base station 230 candecrease with an ensuing reduction in backhaul communication during abase station handoff.

In an aspect, when a number of marked IP data packets or a marking typechanges, an application (not shown), through packet generation component214, can also respond by reducing data transmission rate. As a result,data packet backlog at base station 230 can diminish, which in turnreduces backhaul utilization at base station 230 during handoff. Apotential advantage of active queue management is simplifying interfacesbetween base stations and other elements in the networks, e.g., as tightflow control may not be necessary to maintain a small buffer in the basestation, while still keeping the backhaul utilization low. Additionally,when a mobile terminal that is served by a first base station andreceives IP data packets associated with an application is handed-off toa serving second base station, the data extant in a packet queue in thefirst serving base station (e.g., 230) is efficiently transmitted to thesecond base station via backhaul communication.

Active queue management provided by queue management component 234 canbe based, at least in part, on the size of a data packet queueassociated with a specific application. In addition, or alternatively,queue management component 234 can employ a channel condition (CQI) ofan access terminal (e.g., access terminal 250) conveyed over reverselink 265 to actively manage a queue; for instance, when CQI degradesbelow a threshold, which can be determined by base station 230, beforethe queue becomes large to allow the applications to reduce thetransmission rates. The CQI can be based at on a least one of thefollowing channel condition metrics: a signal-to-interference ratio, asignal-to-noise ratio, a signal-to-interference-and-noise ratio, or thelike.

As mentioned supra, IP data packet(s) 229 are generated trough anapplication, such application can refer to network functions (e.g.,best-effort delivery like transmission control protocol (TCP)) locatedremotely from base station that provide and receive IP packets forcommunication with one or more terminals. The subject applications canhave various latency aspects and QoS; for instance, an application canbe an on-line gaming application (low-latency desired to ensuresatisfactory QoS; commercially relevant application since serviceproviders/carriers can engage users in premium service offering,increasing revenue), a voice over internet protocol (VOIP) application(appreciable latency can be tolerated by a user; however, jitterassociated with poor handoff can have an adverse effect on QoS; itshould be appreciated that systems and method of the subject applicationmitigate jitter by providing efficient handoff data transfer asdiscussed herein), a streaming video application (active queuemanagement can be necessary to ensure that handoff proceeds efficientlythrough low data transfers), a computer operating a system applicationassociated with an access terminal 250 (the computer can be routedthrough an IP core network to network node 210), a custom applicationthat produces data conveyed through best-effort traffic foruser-specific purposes, and the like). In an aspect, an application canreside in network node 210, and a processor 222 can execute at least inpart the application. It should be appreciated that processor 222 canalso execute other operational aspects typical of network node 210.

It should be appreciated that a degree of queue congestion, or a degreeof IP data packet(s) accumulation in a buffer for example, can beaffected by CQI 265, not only directly through explicit incorporation inalgorithms (see below) that dictate the manner in which an IP datapacket is marked or dropped but also indirectly through the rate atwhich an IP data packet is scheduled and communicated. In base station230, scheduler 238 can utilize a received channel state information, orCQI 265, combined with scheduling algorithms (such as round robin, fairqueuing, maximum throughput, proportional fairness, etc.) to scheduledynamically (i) communication resources like bandwidth and frequencyreuse (to reduce other sector interference); (ii) an operation mode ofaccess terminal 250, a mode of operation that can include transmissionin one of single-user single-input multiple-output (SIMO), single-usermultiple-input multiple output (SU-MIMO) or multi-user MIMO (MU-MIMO);and (iii) a code rate and symbol constellation size employed to transmitdata, e.g., IP data packet. Therefore, when large bandwidth andfrequency reuse close to unity, as well as operation in high-capacityMU-MIMO mode is allocated to access terminal 250, a queue associatedwith an application can be decongested, e.g., drained, more readily,thus determining the volume of data packets that are marked or dropped.

In an aspect, reported CQI 265 at access terminal 250 can be determinedbased at least in part on a received known pilot sequence of symbolswhich is transmitted by base station 230. Various sequences can beemployed, for example: a constant amplitude zero autocorrelation (CAZAC)sequence, a pseudorandom code, or a pseudonoise sequence, or a Goldsequence, a Walsh-Hadamard sequence, an exponential sequence, a Golombsequence, a Rice sequence, an M-sequence, or a generalized Chirp-like(GCL) sequence (e.g., Zadoff-Chu sequence). A CQI generation component224 receives the pilot signal, conveyed according to a specific multipleaccess mode of operation (e.g., CDMA, FDMA, or TDMA) and computes achannel condition metric based on said received pilot. Afterdetermination of a CQI value access terminal 250 transmits a CQI channelwhich reports CQI 265.

FIG. 2B illustrates a block diagram of an alternative, or additional,example embodiment 270 that facilitates queue management duringcommunication among a base station 230 and an access terminal 250 in adistributed, data-packet switched wireless network. In exampleembodiment 270, components with like numerals in example system 200have, or provide, substantially the same functionality as described inconnection with components in system 200. In example system 270, IPpacket management is performed in the access terminal 250, through aqueue management component 234. In an aspect, base station 230 inembodiment 270 relays IP packet(s) 229 to access terminal 250, and aqueue is maintained and managed at terminal 250 in substantially thesame manner as described supra in connection with example system 200.

FIG. 2C illustrates a block diagram of another alternative, oradditional, example embodiment 280 that facilitates queue managementduring communication among a base station 230 and an access terminal250, when data packets are generated in an IP node or in the accessterminal 250. In an aspect, access terminal receives IP data packet(s)290 from an IP node 282. As an example, IP node 282 can be a laptopcomputer; however, it should be appreciated that IP node 282 can besubstantially any IP data packet node. Said IP data packet(s) 290 aregenerated by an application component 285 that can be remote to theaccess terminal 250. Said access terminal 250 comprises a queuemanagement component 234 that operates as described above, and canconvey IP data packet(s) 295 which can result from active managementeffected via queue management component 234, or alternatively, caninclude substantially all IP data packet(s) 290 received from IP node282. It should be appreciated that application component 285, whichgenerates the IP data packet(s) 290, can also reside in access terminal250 and can execute an application locally, via processor 258. It shouldbe appreciated that in example embodiment 280, active queue managementis effected in an access terminal and the data packets are conveyed in areverse link (RL).

FIGS. 3A, 3B, and 3C are schematic diagrams 300, 350, and 385 thatillustrate, respectively, a set of example application queues that canbe managed by a queue application management component in example system200, or example embodiment 270, described supra, packet droppingaccording to a predetermined adaptive response function, e.g., adeterministic function or, alternatively a marking/dropping probabilityfunction; and examples of said adaptive response functions. Diagram 300presents four examples queues; however, it should be appreciated thatadditional queues can be managed by queue management component 234. Inan aspect, the number of queues that are managed can depend on theamount of memory available to queue management component 234 and thenumber of processes and threads that processor 242 can support to, atleast in part, execute the operations relevant to queue management(e.g., IP data packet filtering and buffering). Example queues presentedin diagram 300 are a best-effort delivery queue 310A, a streaming videoqueue 310B, a video telephony queue 310C and a VOIP queue 310D. It isnoted that queues 310A and 310B can be actively managed (shown withshaded blocks), whereas queues 310C and 310D may not. Typically, videotelephony and VOIP applications can have tight latency requirements andcan require substantially small buffers. Generally, real-timeapplications and associated IP data packet queues can contributemarginally to utilization of backhaul communication (e.g., link 135)during base station handoff. Thus, substantially marginal active queuemanagement can be necessary.

In an aspect, each queue (e.g., 310A or 310B) associated with one ormore applications (App) can maintain its own average size, e.g., anexponential average size—which can be represented by a buffer 360,typically embodied in a memory—and can have an associated responsefunction (F) that is adaptive dictates whether IP data packets (e.g., IPdata packet(s) 229) associated with the queue (e.g., 310A or 310B) aremarked/dropped. In an aspect, the time-dependent character of a wirelesslink (e.g., forward link 245 and/or reverse link 269), in conjunctionwith the dynamic scheduling (via, for example, scheduler 238) ofcommunication resources, confers response function F its adaptivenature. Response function F can be deterministic, wherein the IP datapackets are marked/dropped based at least in part on whether ageneralized indicator (see below; FIG. 3C) is above or below one or moredynamic (e.g., adaptive) thresholds.

Alternatively, or in addition, marking/dropping of packets can bestochastic, wherein F can be a marking/dropping probability functionthat can depend, for example, on queue size Σ(App), and on othergeneralized indicators (see below) as well. In a case a generalizedindicator is a queue size, it should be appreciated that multiple queuesize thresholds {Σ^((th))(App)} (not shown) can be determined, e.g., bya service provider, and can be exploited to define P(Σ(App)) and thuseffect packet marking/dropping 370. As illustrated in FIG. 3B, if anincoming IP data packet (such as at least one of 380A, 380B, 380C, 380D,or 380E) in the queue is either header-compressed or it is not ExplicitCongestion Notification (ECN) capable, then queue management component234 statistically drops such IP data packet according to, for example amarking/dropping probability function P(Σ(App)). When the incoming IPdata packet is ECN-capable, then packet marking can proceed by settingone or more bits (e.g., a Congestion Experienced bit) in the IP datapacket's header according to probability distribution P(Σ(App)); thelatter marking indicated with dashed lines in packets 380C through 380E.

FIG. 3C illustrates schematic diagrams 385 for response function F intwo instants, τ_(J) and τ_(U), and for two example sets of factors thataffect wireless communication among a base station (e.g., BS 230) and anaccess terminal (e.g., AT 250)—{CQI_(A), BW_(A)} 387A and {CQI_(B),BW_(B)} 387B. Two type of response function F are presented at instantsτ_(J) and τ_(J+1): A stochastic F 389A and a deterministic F 391A. Inthe stochastic case, example response function 389A is dictated by threeparameters; namely, a threshold TH₁ 393A, a threshold TH₂ 395, and aprobability P₂ at threshold TH₂ 395A. In the deterministic case 391A,the response function can adopt two values: 0 and 1, with 1corresponding to marking/dropping a packet, and 0 to incorporating apacket into a queue without marks on it. At instant u, set ofcommunication factors 387B have changed and thus the response functioncan change (e.g., adapt) accordingly. Stochastic function 389B isdetermined by disparate thresholds TH′₁ 393B and TH′₂ 395B and aprobability P′₂; whereas deterministic response function 391B isdictated by a fractional value (e.g., ⅓) between threshold TH′₁ 393Bthreshold TH′₂ 395B. In an aspect, such a fractional value can indicatethe fraction of IP data packets that are deterministically marked ordropped. It should be appreciated that substantially any fractionalvalue can be employed in a deterministic response function. Suchthresholds (at substantially any instant during a communication betweena base station and an access terminal) can correspond to predeterminedvalues of a generalized indicator (G), which can include (1) an averagesize of a queue (e.g., 310A or 310B); (2) a queue delay; (3) anapplication type (e.g., a 32-bit application, or a 64-bit application, amemory intensive application or a processor intensive application, andso on); (4) a frequency reuse parameter; (5) a channel qualityindicator; (6) a number of communication subcarriers; (7) an operationbandwidth; (8) a bandwidth-delay product; (9) a load level in acell/sector served by a base station (e.g., BS 230) that communicateswith an access terminal (e.g., AT 250); (10) a running history of queuesizes, or the like. In another aspect, thresholds associated with astochastic response function can depend primarily on IP data queue sizeand/or packet queuing delay, whereas the slope, e.g., marking/droppingprobability at said thresholds can depend on factor including channelquality indicator, operation bandwidth, frequency reuse factor, and thelike.

It should be appreciated that a set of communication factors, e.g., set387A or set 387B, typically include one or more of possible generalizedindicators G. Moreover, diagrams 385 employ two threshold values forillustrative purposes and not by way of limitation; it is noted thatmultiple thresholds for generalized indicator G can be employed todetermine a response function. The value G_(MAX) 397 associated with ageneralized indicator can correspond to a maximum value that can beassumed by said indicator; for instance, if the generalized indicator isa communication bandwidth, G_(MAX) then corresponds to the largestoperation bandwidth that a base station can utilize to communicate withan access terminal, or the largest BW that the access terminal canemploy for wireless communication. It should be appreciated that whileG_(MAX) for some generalized indicators can be a hard upper bound (e.g.,architecture of the wireless communication network, architecture of amobile terminal, architecture of an eNode B), other maximum values canbe soft and determined, for example, by a service provider.

FIG. 4 is a block diagram 400 of an example base station that comprisesan example queue management component that manages incoming IP datapackets based at least in part on an intelligent component. Base station230 comprises substantially the same functional components/elementsdiscussed above. A scheduler 248 is coupled to processor 242, in turncoupled to a memory 246. A queue management component 410 is coupled toscheduler 248, processor 242 and memory 246, and the functionality ofsaid queue management component 410 is substantially the same as that ofqueue management component 234. Example components and functionalelements included in queue management component 410 provide and expandsaid functionality; however, it should be appreciated that alternativecomponent and functional elements can be employed to the functionalityof component 410 discussed hereinafter.

Queue management component 410 manages IP data packet(s) 229 received atbase station 230 through an intelligent component 420 that relies inalgorithms stored in algorithm store 420 (which in an aspect can beembodied in a memory). For example, said algorithms can include at leastone of a random early detection (RED) algorithm or an explicitcongestion notification (ECN) algorithm. It is noted that intelligentcomponent can optimize a set of parameters (e.g., marking/droppingprobability function, a minimum threshold for queue size, a maximumthreshold for queue size, and exponential average constant, or a maximumlikelihood of marking/dropping when a queue is at the maximum thresholdsize) that enter the RED algorithm in order to obey the followingtargets: (i) TCP traffic queue (e.g., best-effort delivery queue 310A)aims to be non-empty at substantially all times, even after the TCPapplication reacts to an early congestion signal (e.g., markingindicator 248). Such target can prevent loss of over-the-air efficiencyand loss of multi-user diversity—particularly critical in themultiple-user multiple-input multiple-output (MU-MIMO) operation mode ofbase station 230 and access terminal 250. (ii) Buffered data isminimized so that backhaul utilization is also minimized whenever BS-BShandoff occurs. It is readily apparent that targets (i) and (ii),individually tent to disparate maxima in a phase space of parameters.Furthermore said algorithms can provide for introducing responsefunctions, e.g., marking/dropping probability functions, that depend ona size of a queue (e.g., streaming video 310B) associated with anapplication that conveys IP data packet(s) 229. In addition, algorithmsresiding in algorithm store 430 can afford marking or dropping IP datapacket(s) 229 according to thresholds in a buffer (e.g., buffer 360)size when executed, at least in part, in processor 242. Furthermore,algorithms in algorithm store 430 also afford the functionalitiesassociated with intelligent component 420 (see below) when executed, atleast in part, in processor 242. In particular, intelligent component420 can mark or drop IP data packet(s) 229 based at least in part on CQIintelligence 440 (typically embodied in a memory) or upon user/terminalintelligence 440 (typically embodied in a memory). It is noted thatintelligent component 420 can rely on substantially any intelligencecollected in connection with substantially any generalized indicator,such as the aforementioned example generalized indicators (1)-(10) inconnection with the discussion of FIG. 3C.

In an aspect, CQI intelligence 430 can include seasonal records of CQI.In an aspect, the records can include filtered CQI values determined inthe last Δτ seconds. In another aspect, said seasonal records can spanat least one of the following example time intervals: a summer season ora winter season, a specific month, a specific time of day like rush hour(which can be important for a base station operating near a highway,wherein inter-cell interference can dramatically increase during trafficjams), or the like. Such CQI records can be associated with terminalsoperating in a service cell/sector covered by base station 230; and suchdata can be incorporated into algorithms in algorithm store 430 andemployed for IP data packet(s) 229 marking or dropping. In particularthe response function F, either a deterministic function or amarking/dropping probability function (P), that determines thelikelihood that a packet is marked or dropped can depend explicitly onCQI, either measured on real time or stored in CQI intelligence 440, oron substantially any generalized indicator G.

It should be appreciated that since a base station, e.g., base station230, or a sector (e.g., sector 104 a) utilize IP mobility to route userdata packets among base stations or sectors upon handoff, this allows abase station 230 or sector 104 a to detect and determine the destination(e.g., user) of IP data packet(s) 229 being routed to an accessterminals (e.g., access terminal 250). Additionally, in an aspect, IPdata packet(s) are associated to a specific application, as discussedsupra. Thus, intelligent component 410 can determine that a set of IPdata packets are to be retained despite excessive buffer size in view ofthe specific characteristics of a user or terminal to which the data istransmitted. For example, a premium user employing a streaming videoapplication can continue receiving data packets regardless the size of abuffer associated to the application. In such a scenario, users that arenot premium users can experience a reduction in the flow of data, inorder to maintain an overall buffer size in the base station thatensures efficient handover. In another example, an access terminalreceiving critical information/data, e.g., medical records of a woundedsoldier in the battlefield, conveyed by a specific application such as adatabase server, can retain data flow despite associate buffer size; asin the preceding example, applications that intelligent component inferthat convey less critical information can experience a larger thantypical number of IP data packets in order to retain an adequate buffersize for effective base station handoff. It should be appreciated thatinferences associated to marking/dropping data packets associated with aspecific application or user are conducted in an automated manner.

As employed hereinbefore, the term “intelligent,” or “intelligence”refers to the ability to reason or draw conclusions about, e.g., infer,the current or future state of a system based on existing informationabout the system. Artificial intelligence can be employed to identify aspecific context or action, or generate a probability distribution ofspecific states of a system without human intervention. Artificialintelligence relies on applying advanced mathematical algorithms—e.g.,decision trees, neural networks, regression analysis, cluster analysis,genetic algorithms, and reinforced learning—to a set of available data(information) on the system. Said algorithms can be retained in analgorithm store (such as algorithm store 430), as available systeminformation can be maintained in a memory residing in the system (suchas memory 246).

In particular, to the accomplishment of the various automated aspectsdescribed above in connection with policies for load indicatorgeneration and other automated aspects relevant to the subjectinnovation described herein, an AI component (e.g., component 320) canemploy one of numerous methodologies for learning from data and thendrawing inferences from the models so constructed, e.g., Hidden MarkovModels (HMMs) and related prototypical dependency models, more generalprobabilistic graphical models, such as Bayesian networks, e.g., createdby structure search using a Bayesian model score or approximation,linear classifiers, such as support vector machines (SVMs), non-linearclassifiers, such as methods referred to as “neural network”methodologies, fuzzy logic methodologies, and other approaches thatperform data fusion, etc.

In addition to intelligence in the aforementioned context of AI,intelligence can describe specific information that characterizes anentity, e.g., a user, an access terminal, or historical eventsidentified through behaviors or conditions, or indicators associatedthereof or with variables that characterize such behaviors orconditions; e.g., channel state conditions associated with the physicalproperties of a wireless communication channel characterized through aspecific indicator like a CQI. With respect to user intelligence,information contained in such intelligence can reflect the user'spersonal history or behavior, and records of commercial andnon-commercial activities (acquiring premium services from a serviceprovider, or adopting edge technology embodied in novel accessterminals. for example) involving a product or a service. Information onfeatures that identify an access terminal (e.g., capable ofmultiple-system operation, such as UMB, LTE, and IEEE 802, bandwidthflexibility, multiple antennas, and so forth) employed by a user can becollected and retained as terminal intelligence, typically embodied in amemory.

FIG. 5 is a block diagram of an example system 500 that facilitatesrelaying IP data packet(s) among base stations prior to handoff. System500 comprises two base stations 510A and 510B that include substantiallythe same functional component as base station 230, and operate insubstantially the same manner. It should be appreciated that backhaulcommunication (e.g., link 135) or an idle access terminal (not shown)can be exploited to relay IP data packets 520 among base stations 5110Aand 510B. Data packet relay provides at least the advantage to avoiddropping IP data packets. Data relay can originate in multiple factors:(i) Channel conditions can be poor (e.g., large intra-cell and othersector interference, temporary changes in cell/sector landscape leadingto increased channel fading, and so on) and fewer terminals arescheduled such that a substantive number of IP data packet(s) 229 is tobe dropped in order to keep buffer size within predetermined thresholds.(ii) A set of premium users demanding a large flow of data for criticalapplications. Such a situation can occur when an emergency,environmental or otherwise, takes place and critical data is transmittedfrom network node 210 to a relaying base station (e.g., base station510A). (iii) An inference, via for example an intelligent module inqueue management component 234 residing in base station 510A, is made asto which base station are to be involved in handoff for a specificuser/terminal; depending on the application said user/terminal isemploying, IP data packets can be relayed in anticipation to basestation handoff among base stations 510A and 510B. Such an inference canbe generated based at least in part on available user/terminalintelligence (e.g., user/terminal intelligence 450) in queue managementcomponent 234 in base station 510A.

In an aspect, unless base station handoff for a terminal involves basestation 510A and 510B, relayed data reside temporarily in the basestation that received the data. The time span of relayed date in a relaybase station can be determined/inferred based on CQI intelligencerelated to the sector/cell served by the base station that conveys (orrelays) the fraction of IP data packet(s) 520. For example, relayed datacan reside in the relay base station (e.g., base station 510B) for aperiod of time spanning milliseconds to seconds and minutes.

It is noted that data relay among base stations 510A and 510B throughbackhaul utilization can be submitted to scheduling constraints atnetwork node 210, or it can be scheduled by scheduler 238 in therelaying (e.g., data conveying) base station. Furthermore, IP datapacket relay 520 effected through an idle access terminal can demandpreservation of data integrity and fraud mitigation, as data isscheduled and routed into a third party terminal. In an aspect, relayedIP data packets 520 can be encrypted and public keys can be employed bythe relay base station (e.g., base station 510B) and the third-partyaccess terminal. In another aspect, a dedicated system code introducedby a service provider at the time of third-party terminal activation canbe employed to convey relay data only through the third-party terminal.

FIG. 6 illustrates a block diagram of an example system 600 thatfacilitates IP data packet(s) management based on reconfiguration of theoperation of an access terminal that consumes the data packets. System600 can incorporate extrinsic queue management through (re)allocation ofcommunication resources for an access terminal 250 that receives IP datapacket(s) 610. The extrinsic character of the queue management affordedby example system 600 can be reflected in the fact that buffer/queuesize is controlled by reconfiguring the wireless communication linkrather than, or in complement to, queue management attained throughqueue management component 234 in base station 234. An advantage of theextrinsic queue management is that buffer size can be optimized for theaccess terminal 250 that consumes the data packets and the wirelesschannel conditions (e.g., CQI 630) at substantially the time of basehandoff. It should be appreciated that extrinsic queue management is notused to solve synchronization issues because an access terminal'straffic is buffered on a per flow basis. Base station 230 comprises aqueue management component 234, a scheduler 238, a processor 242, and amemory 246; functionality of these components has been described supra.Access terminal 250 includes a CQI generation component 254, a processor258, and a memory 262, which have been described above.

To accomplish extrinsic queue management, in an aspect, operationbandwidth BW of access terminal 250 can be adjusted to ensure that thesize of a queue (not shown) associated with an application consumed byaccess terminal 250 is maintained at a size below at least one of aplurality of thresholds, or at a size Σ that ensures a predeterminedmarking/dropping probability function P(Σ(App)) of marking/dropping anIP data packet. It should be appreciated that such a size can be a tradeoff between engaging in a reconfiguration of access terminal 250, aprocess that can involve resynchronization, at least partially, ofterminal 250. In order to adjust the bandwidth of mobile 250, abandwidth indicator 620 is transmitted to the mobile via FL 605, forexample BW indicator 620 can be transmitted as K bits (wherein K is apositive integer) in a primary control channel or secondary controlchannel. BW indicator 620 can convey to access terminal 250 a bandwidththat is adequate to attain a specific data rate that can lead to apredetermined size Σ(App) of a queue that is managed by base station230. In turn, access terminal transmits to the base station, throughreverse link 625, (i) a CQI 630 that indicates the channel conditions ofoperation, (ii) a bandwidth offset indicator 640 that indicates anadjustment to be made to the originally conveyed BW in ΔBW indicator620, and (iii) a power indicator 650 that can ensure adequate powerspectral density operation based on reconfigured BW; which depends on BWindicator 620 and ΔBW indicator 640. In an aspect, the power indicator650 can be conveyed as Q bits (Q a positive integer) in at least one ofa primary synchronization channel or a secondary synchronizationchannel. Upon receiving CQI 630, the bandwidth offset 640 and the powerindicator 650, scheduler (re)assigns communication resources to accessterminal 250 and requests queue management component 234 to drain abuffer associated with the application (not shown) utilized by accessterminal 250.

FIG. 7 is a block diagram 700 of an embodiment of a transmitter system710 (such as Node B 230) and a receiver system 750 (e.g., accessterminal 250) in a multiple-input multiple-output (MIMO) system that canprovide for cell (or sector) communication in a wireless environment inaccordance with one or more aspects set forth herein. At the transmittersystem 710, traffic data for a number of data streams can be providedfrom a data source 712 to transmit (TX) data processor 714. In anembodiment, each data stream is transmitted over a respective transmitantenna. TX data processor 714 formats, codes, and interleaves thetraffic data for each data stream based on a particular coding schemeselected for that data stream to provide coded data. The coded data foreach data stream may be multiplexed with pilot data using OFDMtechniques. The pilot data is typically a known data pattern that isprocessed in a known manner and can be used at the receiver system toestimate the channel response. The multiplexed pilot and coded data foreach data stream is then modulated (e.g., symbol mapped) based on aparticular modulation scheme (e.g., binary phase-shift keying (BPSK),quadrature phase-shift keying (QPSK), multiple phase-shift keying(M-PSK), or m-order quadrature amplitude modulation (M-QAM)) selectedfor that data stream to provide modulation symbols. The data rate,coding, and modulation for each data stream may be determined byinstructions executed by processor 730, the instructions as well as thedata may be stored in memory 732.

The modulation symbols for all data streams are then provided to a TXMIMO processor 720, which may further process the modulation symbols(e.g., OFDM). TX MIMO processor 720 then provides N_(T) modulationsymbol streams to N_(T) transceivers (TMTR/RCVR) 722 _(A) through 722_(T). In certain embodiments, TX MIMO processor 720 applies beamformingweights (or preceding) to the symbols of the data streams and to theantenna from which the symbol is being transmitted. Each transceiver 722receives and processes a respective symbol stream to provide one or moreanalog signals, and further conditions (e.g., amplifies, filters, andupconverts) the analog signals to provide a modulated signal suitablefor transmission over the MIMO channel. N_(T) modulated signals fromtransceivers 722 _(A) through 722 _(T) are then transmitted from N_(T)antennas 724 ₁ through 724 _(T), respectively. At receiver system 750,the transmitted modulated signals are received by N_(R) antennas 752 ₁through 752 _(R) and the received signal from each antenna 752 isprovided to a respective transceiver (RCVR/TMTR) 754 _(A) through 754_(R). Each transceiver 754 ₁-754 _(R) conditions (e.g., filters,amplifies, and downconverts) a respective received signal, digitizes theconditioned signal to provide samples, and further processes the samplesto provide a corresponding “received” symbol stream.

An RX data processor 760 then receives and processes the N_(R) receivedsymbol streams from N_(R) transceivers 754 ₁-754 _(R) based on aparticular receiver processing technique to provide N_(T) “detected”symbol streams. The RX data processor 760 then demodulates,deinterleaves, and decodes each detected symbol stream to recover thetraffic data for the data stream. The processing by RX data processor760 is complementary to that performed by TX MIMO processor 720 and TXdata processor 714 at transmitter system 710. A processor 770periodically determines which pre-coding matrix to use; such a matrixcan be stored in memory 772. Processor 770 formulates a reverse linkmessage comprising a matrix index portion and a rank value portion.Memory 772 may store instructions that when executed by processor 770result in formulating the reverse link message. The reverse link messagemay comprise various types of information regarding the communicationlink or the received data stream, or a combination thereof. As anexample, such information can comprise channel quality indication(s)(such as CQI 265 or CQI 630), an offset for adjusting a scheduledresource (such as ΔBW indicator 640), and/or sounding reference signalsfor link (or channel) estimation. The reverse link message is thenprocessed by a TX data processor 738, which also receives traffic datafor a number of data streams from a data source 736, modulated by amodulator 780, conditioned by transceiver 754 _(A) through 754 _(R), andtransmitted back to transmitter system 710.

At transmitter system 710, the modulated signals from receiver system750 are received by antennas 724 ₁-724 _(T), conditioned by transceivers722 _(A)-722 _(T), demodulated by a demodulator 740, and processed by aRX data processor 742 to extract the reserve link message transmitted bythe receiver system 750. Processor 730 then determines which pre-codingmatrix to use for determining the beamforming weights and processes theextracted message.

As discussed above, in connection with FIG. 2, receiver 750 can bedynamically scheduled to operate in SIMO, SU-MIMO, and MU-MIMO. Next,communication in these modes of operation is described. It is noted thatin SIMO mode a single antenna at the receiver (N_(R)=1) is employed forcommunication; therefore, SIMO operation can be interpreted as a specialcase of SU-MIMO. Single-user MIMO mode of operation corresponds to thecase in which a single receiver system 750 communicates with transmittersystem 710, as previously illustrated FIG. 7 and according to theoperation described in connection therewith. In such a system, the N_(T)transmitters 724 ₁-724 _(T) (also known as TX antennas) and N_(R)receivers 752 ₁-752 _(R) (also known as RX antennas) form a MIMO matrixchannel (e.g., Rayleigh channel, or Gaussian channel, with slow or fastfading) for wireless communication. As mentioned above, the SU-MIMOchannel is described by a N_(R)×N_(T) matrix of random complex numbers.The rank of the channel equals the algebraic rank of the N_(R)×N_(T)matrix, which in terms of space-time, or space-frequency coding, therank equals the number N_(V)≦min{N_(T), N_(R)} of independent datastreams (or layers) that can be sent over the SU-MIMO channel withoutinflicting inter-stream interference.

In one aspect, in SU-MIMO mode, transmitted/received symbols with OFDM,at tone ω, can be modeled by:y(ω)=H(ω)c(ω)+n(ω).  (1)Here, y(ω) is the received data stream and is a N_(R)×1 vector, H(ω) isthe channel response N_(R)×N_(T) matrix at tone ω (e.g., the Fouriertransform of the time-dependent channel response matrix h), c(ω) is anN_(T)×1 output symbol vector, and n(ω) is an N_(R)×1 noise vector (e.g.,additive white Gaussian noise). Precoding can convert a N_(V)×1 layervector to N_(T)×1 precoding output vector. N_(V) is the actual number ofdata streams (layers) transmitted by transmitter 710, and N_(V) can bescheduled at the discretion of the transmitter (e.g., transmitter 710,Node B 250, or access point 110) based at least in part on channelconditions (e.g., reported CQI 630) and the rank reported in ascheduling request by a terminal (e.g., receiver 650). It should beappreciated that c(ω) is the result of at least one multiplexing scheme,and at least one pre-coding (or beamforming) scheme applied by thetransmitter. Additionally, c(ω) is convoluted with a power gain matrix,which determines the amount of power a scheduler 238 in base station 230allocates to transmit each data stream N_(V). It should be appreciatedthat such a power gain matrix can be a resource that is assigned to aterminal (e.g., access terminal 250), and it can be controlled throughpower indicator 750.

As mentioned above, according to an aspect, MU-MIMO operation of a setof access terminals (e.g., mobile 250) is within the scope of thesubject innovation. Moreover, scheduled MU-MIMO terminals operatejointly with SU-MIMO terminals and SIMO terminals. FIG. 8 illustrates anexample multiple-user MIMO system 800 in which three ATs 750 _(P), 750_(U), and 750 _(S), embodied in receivers substantially the same asreceiver 750, communicate with transmitter 710, which embodies a Node B.It should be appreciated that operation of system 800 is representativeof operation of substantially any group (e.g., 185) of wireless devices,such as terminal 250, scheduled in MU-MIMO operation within a servicecell by a centralized scheduler residing in a serving access point(e.g., 110 or 250). As mentioned above, transmitter 710 has N_(T) TXantennas 724 ₁-724 _(T), and each of the ATs has multiple RX antennas;namely, AT_(P) has N_(P) antennas 752 ₁-752 _(P), AP_(U) has N_(U)antennas 752 ₁-752 _(U), and AP_(S) has N_(S) antennas 752 ₁-752 _(S).Communication between terminals and the access point is effected throughuplinks 815 _(P), 815 _(U), and 815 _(S). Similarly, downlinks 810 _(P),810 _(U), and 810 _(S) facilitate communication between Node B 710 andterminals AT_(P), AT_(U), and AT_(S), respectively. Additionally,communication between each terminal and base station is implemented insubstantially the same manner, through substantially the samecomponents, as illustrated in FIG. 7 and its corresponding description.

Terminals can be located in substantially different locations within thecell serviced by access point 710 (e.g., cell 180), therefore each userequipment 750 _(P), 750 _(U), and 750 _(S) has its own MIMO matrixchannel h_(α) and response matrix H_(α) (α=P, U, and S), with its ownrank (or, equivalently, singular value decomposition). Intra-cellinterference can be present due to the plurality of users present in thecell serviced by the base station 710. Such interference can affect CQIvalues reported by each of terminals 750 _(P), 750 _(U), and 750 _(S).Similarly, interference also can affect feed back values of poweroffsets (e.g., ΔPSD 243) employed for power control at Node B 710.

Although illustrated with three terminals in FIG. 8, it should beappreciated that a MU-MIMO system can comprise any number of terminals,each of such terminals indicated below with an index k. In accordancewith various aspects, each of the access terminals 750 _(P), 750 _(U),and 750 _(S) can report CQI from a single antenna and can convey a PSDoffset feedback, associated with such single antenna, to Node B 710. Inaddition, each of such terminals can transmit to Node B 710 soundingreference signals from each antenna in the set of antennas employed forcommunication. Node B 710 can dynamically re-schedule each of terminals750 _(P), 750 _(U), and 750 _(S) in a disparate mode of operation suchas SU-MIMO or SIMO.

In one aspect, transmitted/received symbols with OFDM, at tone ω and foruser k, can be modeled by:y _(k)(ω)=H _(k)(ω)c _(k)(ω)+H _(k)(ω)Σ′c _(m)(ω)+n _(k)(ω).  (2)Here, symbols have the same meaning as in Eq. (1). It should beappreciated that due to multi-user diversity, other-user interference inthe signal received by user k is modeled with the second term in theleft-hand side of Eq. (3). The prime (′) symbol indicates thattransmitted symbol vector c_(k) is excluded from the summation. Theterms in the series represent reception by user k (through its channelresponse H_(k)) of symbols transmitted by a transmitter (e.g., accesspoint 250) to the other users in the cell.

In view of the example systems presented and described above,methodologies for inter-cell power controls that may be implemented inaccordance with the disclosed subject matter will be better appreciatedwith reference to the flowcharts of FIGS. 9 and 10. While, for purposesof simplicity of explanation, the methodologies are shown and describedas a series of blocks, it is to be understood and appreciated that theclaimed subject matter is not limited by the number or order of blocks,as some blocks may occur in different orders and/or concurrently withother blocks from what is depicted and described herein. Moreover, notall illustrated blocks may be required to implement the methodologiesdescribed hereinafter. It is to be appreciated that the functionalityassociated with the blocks may be implemented by software, hardware, acombination thereof or any other suitable means (e.g., device, system,process, component, . . . ). Additionally, it should be furtherappreciated that the methodologies disclosed hereinafter and throughoutthis specification are capable of being stored on an article ofmanufacture to facilitate transporting and transferring suchmethodologies to various devices. Those skilled in the art willunderstand and appreciate that a methodology could alternatively berepresented as a series of interrelated states or events, such as in astate diagram.

FIG. 9 presents a flowchart of an example method for managing a dataqueue in a base station that operates in a wireless distributed networkand facilitating base station handoff. At step 910 an IP data packetassociated with an application and an access terminal is received. Forexample, IP data packet can be generated by an application that isexecuted remotely and can convey streamlined data or asynchronous data.For example, an application that can convey data asynchronously can be aweb-based game, or a web-based browser. It should be appreciated thatother applications are within the scope of the subject innovation. In anaspect, a data packet is created in a network node, through a packetgeneration component (FIG. 1), which can execute one or moreapplications; however, routing of the packet associated with theapplication can take place in the base station. In another aspect, thedata packet can be created in an access terminal executing anapplication. In such a case data packets can be conveyed in a reverselink (e.g., RL) At act 920, the received IP data packets are filteredand buffered, and a packet queue is assigned to the applicationassociated with the data packets. In one aspect, filtering and bufferingcan be accomplished through a queue management component (e.g.,component 234) that can reside in a base station (e.g., base station230)

At act 930 a first set of IP data packets, which can be buffered, withinthe packet queue associated with the application executed remotely ismarked or dropped based at least in part on a response function thatdepends on a communication generalized indicator. The response functioncan be deterministic or stochastic, and the details of response functiondependence on a communication generalized indicator can be determined bya service provider that facilitates wireless communication between abase station and an access terminal. A generalized communicationindicator is a parameter that can characterize the wirelesscommunication, the application that is being executed, or the queueassigned to the executed application. Examples of generalizedcommunication indicators can include (i) an average size of a queue(e.g., 310A or 310B); (ii) a queue delay; (iii) an application type(e.g., a 32-bit application, or a 64-bit application, a memory intensiveapplication or a processor intensive application, and so on); (iv) afrequency reuse parameter; (v) a channel quality indicator; (vi) anumber of communication subcarriers; (vii) an operation bandwidth;(viii) a bandwidth-delay product; (ix) a load level in a cell/sectorserved by a base station (e.g., BS 230) that communicates with an accessterminal (e.g., AT 250); (x) a running history of queue sizes, or thelike. In the case of a deterministic response function, in one aspect, apacket is marked of dropped according to the specific value of acommunication generalized indicator that is employed to monitor theapplication queue evolution. In another aspect, a deterministic responsefunction can convey a rate of marking/dropping an IP data packet througha fractional value (391B; FIG. 3C). In the case of a stochastic responsefunction is a probability distribution that provides with a probabilityfor marking or dropping the IP data packets. In an aspect, a queuemanagement component (FIG. 1) that can reside within the base stationprovides such marking/dropping.

At act 940, a second set of IP data packets associated with theapplication or an access terminal can be conveyed. Conveying the datapacket can typically entail transmitting the data according to scheduledresources for the access terminal associated with the data packets.

FIG. 10 presents a flowchart of an example method 1000 for managing adata queue in a base station that operates in a wireless distributednetwork and facilitating base station handoff in accordance with anaspect. At act 1010, a set of adaptive thresholds for a communicationgeneralized indicator is determined. Such determination can be madebased on specific target for the size of an application queue, in orderto ensure efficient base station handoff. Typically, such a target sizerepresents a trade off among disparate objective functions; forinstance, a first objective function can tend to maintain a large queuesize in order to increase the likelihood data packets are transmitted,whereas a second objective function can tend to maintain a small queuesize in order to ensure efficient base station handoff. Alternatively,or in addition, determination of thresholds can be based on intelligencecollected on historical values of communication generalized indicators,as well as to optimize performance of an application or access terminal,or maintain a target level of QoS.

The determined set of thresholds is adaptive in that a threshold canchange dynamically in response to the values adopted by otherthresholds, such as channel state conditions, application queue size,queuing delay, communication bandwidth, bandwidth-delay product, and soon.

At act 1020 a response function is determined according to thedetermined set of adaptive thresholds for a communicator generalizedindicator. In the case of a deterministic response function, the set ofthresholds determined whether an IP data packet is marked or dropped;for instance, data packets can be dropped once a communicatorgeneralized indicator is above a maximum threshold (FIG. 3C). Such acommunication generalized indicator can be a data packet buffer size, orit can be channel quality indicator associated with a communicationchannel, or it can be substantially any of the aforementionedcommunication generalized indicators. In the case of stochastic responsefunction, the set of adaptive thresholds can determine intervals inwhich the probability to mark of drop a packet can have a specificdependence on the communication generalized indicator.

At act 1030, an IP data packet in an application queue is marked ordropped based at least in part on the response function that determinedresponse function.

Next, example systems that can enable aspects of the disclosed subjectedmatter are described in connection with FIGS. 11 and 12. Such systemscan include functional blocks, which can be functional blocks thatrepresent functions implemented by a processor or an electronic machine,software, or combination thereof (e.g., firmware).

FIG. 11 illustrates a block diagram of an example system that enablesmanaging a queue in a base station according to aspects describedherein. System 1100 can reside, at least partially, within a basestation (e.g., BS 230). System 1100 includes a logical grouping 1110 ofelectronic components that can act in conjunction. In an aspect, logicalgrouping 1110 includes an electronic component 1115 for receiving a setof internet-protocol (IP) data packets associated with acomputer-implemented application executing remotely; an electroniccomponent 1125 for assigning a data packet queue to the received set ofIP data packets; an electronic component 1135 for marking or dropping asubset of the IP data packets in the received set of IP data packetsbased at least in part on an adaptive communication generalizedindicator and an associated threshold thereof. In addition, system 1100can include electronic component 1145 for receiving the adaptivecommunication generalized indicator and the associated thresholdthereof, an electronic component 1155 for conveying a complementary setof IP data packets associated with the application and extant in thedata packet application queue. In addition, electronic grouping 1110 caninclude an electronic component 1165 for receiving a marking indicator.

System 1100 can also include a memory 1180 that retains instructions forexecuting functions associated with electrical components 1115, 1125,1135, 1145, 1155, and 1165, as well as measured and/or computed datathat may be generated during executing such functions. While shown asbeing external to memory 1170, it is to be understood that one or moreof electronic components 1115, 1125, 1135, 1145, 1155, and 1165 canexist within memory 1170.

FIG. 12 illustrates a block diagram of an example system that enablesmanaging a queue in an access terminal according to aspects describedherein. System 1200 can reside, at least partially, within an accessterminal (e.g., AT 250). System 1200 includes a logical grouping 1210 ofelectronic components that can act in conjunction. In an aspect, logicalgrouping 1210 includes an electronic component 1215 for receiving aninternet-protocol (IP) data packet generated by a computer-implementedapplication; an electronic component 1225 for buffering the received IPdata packet; an electronic component 1235 for marking or dropping thereceived IP data packet according to a deterministic or stochasticresponse function; and an electronic component 1245 for conveying amarked IP data packet. In addition, electronic grouping 1210 can includean electronic component 1255 for generating an IP data packet; anelectronic component 1265 for marking or dropping the generated datapacket; an electronic component 1275 for conveying at least one of thegenerated IP data packet or marked IP data packet; and an electroniccomponent 1285 for conveying the received IP data packet.

System 1200 can also include a memory 1290 that retains instructions forexecuting functions associated with electrical components 1215, 1225,1235, 1245, 1255, 1265, 1275 and 1285, as well as measured and/orcomputed data that may be generated during executing such functions.While shown as being external to memory 1280, it is to be understoodthat one or more of electronic components 1215, 1225, 1235, 1245, 1255,1265, 1275 and 1285 can exist within memory 1290.

For a software implementation, the techniques described herein may beimplemented with modules (e.g., procedures, functions, and so on) thatperform the functions described herein. The software codes may be storedin memory units and executed by processors. The memory unit may beimplemented within the processor or external to the processor, in whichcase it can be communicatively coupled to the processor via variousmeans as is known in the art.

Various aspects or features described herein may be implemented as amethod, apparatus, or article of manufacture using standard programmingand/or engineering techniques. The term “article of manufacture” as usedherein is intended to encompass a computer program accessible from anycomputer-readable device, carrier, or media. For example,computer-readable media can include but are not limited to magneticstorage devices (e.g., hard disk, floppy disk, magnetic strips, etc.),optical disks (e.g., compact disk (CD), digital versatile disk (DVD),etc.), smart cards, and flash memory devices (e.g., EPROM, card, stick,key drive, etc.). Additionally, various storage media described hereincan represent one or more devices and/or other machine-readable mediafor storing information. The term “machine-readable medium” can include,without being limited to, wireless channels and various other mediacapable of storing, containing, and/or carrying instruction(s) and/ordata.

As it employed herein, the term “processor” can refer to a classicalarchitecture or a quantum computer. Classical architecture comprises,but is not limited to comprising, single-core processors;single-processors with software multithread execution capability;multi-core processors; multi-core processors with software multithreadexecution capability; multi-core processors with hardware multithreadtechnology; parallel platforms; and parallel platforms with distributedshared memory. Additionally, a processor can refer to an integratedcircuit, an application specific integrated circuit (ASIC), a digitalsignal processor (DSP), a field programmable gate array (FPGA), aprogrammable logic controller (PLC), a complex programmable logic device(CPLD), a discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. Quantum computer architecture may be based on qubitsembodied in gated or self-assembled quantum dots, nuclear magneticresonance platforms, superconducting Josephson junctions, etc.Processors can exploit nano-scale architectures such as, but not limitedto, molecular and quantum-dot based transistors, switches and gates, inorder to optimize space usage or enhance performance of user equipment.A processor may also be implemented as a combination of computingdevices, e.g., a combination of a DSP and a microprocessor, a pluralityof microprocessors, one or more microprocessors in conjunction with aDSP core, or any other such configuration.

Furthermore, in the subject specification, the term “memory” refers todata stores, algorithm stores, and other information stores such as, butnot limited to, image store, digital music and video store, charts anddatabases. It will be appreciated that the memory components describedherein can be either volatile memory or nonvolatile memory, or caninclude both volatile and nonvolatile memory. By way of illustration,and not limitation, nonvolatile memory can include read only memory(ROM), programmable ROM (PROM), electrically programmable ROM (EPROM),electrically erasable ROM (EEPROM), or flash memory. Volatile memory caninclude random access memory (RAM), which acts as external cache memory.By way of illustration and not limitation, RAM is available in manyforms such as synchronous RAM (SRAM), dynamic RAM (DRAM), synchronousDRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM(ESDRAM), Synchlink DRAM (SLDRAM), and direct Rambus RAM (DRRAM).Additionally, the disclosed memory components of systems and/or methodsherein are intended to comprise, without being limited to, these and anyother suitable types of memory.

What has been described above includes examples of one or moreembodiments. It is, of course, not possible to describe everyconceivable combination of components or methodologies for purposes ofdescribing the aforementioned embodiments, but one of ordinary skill inthe art may recognize that many further combinations and permutations ofvarious embodiments are possible. Accordingly, the described embodimentsare intended to embrace all such alterations, modifications andvariations that fall within the spirit and scope of the appended claims.Furthermore, to the extent that the term “includes,” “including,” “has,”having,” or variants thereof are used in either the detailed descriptionor the claims, such terms are intended to be inclusive in a mannersimilar to the term “comprising” as “comprising” is interpreted whenemployed as a transitional word in a claim.

The invention claimed is:
 1. A base station in a wireless communicationsnetwork, comprising: a processor configured to: receive a set ofinternet-protocol (IP) data packets generated by a computer-implementedapplication, wherein the computer implemented application executesremotely; assign a data packet queue to the received set of IP datapackets; mark a subset of the IP data packets in the received set of IPdata packets for adjusting a generation rate of the IP data packetsbased at least in part on a response function that depends on anadaptive communication generalized indicator; and convey, at a reducedrate relative to a rate of the received set of IP data packets, acomplementary set of IP data packets associated with the application andextant in the data packet queue, based on the marked subset of the IPdata packets, to a disparate base station through backhaul networkcommunication; and a memory coupled to the processor.
 2. The basestation of claim 1, wherein the processor is further configured toreceive the adaptive communication generalized indicator.
 3. The basestation of claim 2, wherein the adaptive communication generalizedindicator is determined based at least on one of an average queue size,a running history of queue sizes, a queue delay, a channel qualityindicator, an operation bandwidth, a bandwidth-delay product, afrequency reuse parameter, or a load level in a communication sector. 4.The base station of claim 3, wherein the processor is further configuredto mark or drop the subset of IP data packets based at least in part ona set of adaptive thresholds for the adaptive communication generalizedindicator.
 5. The base station of claim 3, wherein the processor isfurther configured to convey the marking indicator.
 6. The base stationof claim 1, wherein the processor is further configured to receive amarking indicator.
 7. The base station of claim 1, wherein the processoris further configured to convey the data packet queue at a time of ahandoff event.
 8. A base station that operates in a wirelesscommunications system, the base station comprising: means for receivinga set of internet-protocol (IP) data packets generated by acomputer-implemented application, wherein the computer-implementedapplication executes remotely; means for assigning a data packet queueto the received set of IP data packets; means for marking a subset ofthe IP data packets in the received set of IP data packets for adjustinga generation rate of the IP data packets based at least in part on aresponse function that depends on an adaptive communication generalizedindicator; and means for conveying, at a reduced rate relative to a rateof the received set of IP data packets, a complementary set of IP datapackets associated with the application and extant in the data packetqueue, based on the marked subset of the IP data packets, to a disparatebase station through backhaul network communication.
 9. The base stationof claim 8, wherein the means for conveying is further configured toconvey the data packet queue at a time of a handoff event.
 10. A methodutilized in a wireless communication system, the method comprising:receiving, by a base station, a set of internet-protocol (IP) datapackets generated by a computer-implemented application, wherein thecomputer implemented application executes remotely; assigning a datapacket queue to the received set of IP data packets; marking, by thebase station, a subset of the IP data packets in the received set of IPdata packets for adjusting a generation rate of the IP data packetsbased at least in part on a response function that depends on anadaptive communication generalized indicator; and conveying, at areduced rate relative to a rate of the received set of IP data packets,a complementary set of IP data packets associated with the applicationand extant in the data packet queue, based on the marked subset of theIP data packets, to a disparate base station through backhaul networkcommunication.
 11. The method of claim 10, further comprising receivingthe adaptive communication generalized indicator.
 12. The method ofclaim 11, wherein the adaptive communication generalized indicatordetermined based at least on one of an average queue size, a runninghistory of queue sizes, a queue delay, a channel quality indicator, anoperation bandwidth, a bandwidth-delay product, a frequency reuseparameter, or a load level in a communication sector.
 13. The method ofclaim 12, wherein the response function is a stochastic functiondefining a first threshold and a second threshold and a markingprobability as a function of the adaptive communication generalizedindicator as the adaptive communication generalized indicator increases.14. The method of claim 13, wherein the response function is adeterministic function based on at least a fractional value of adifference of the first threshold and second threshold as a function ofthe adaptive communication generalized indicator as the adaptivecommunication generalized indicator increases.
 15. The method of claim10, further comprising generating a set of IP data packets.
 16. Themethod of claim 15, further comprising assigning a queue associated tothe generated set of IP data packets.
 17. The method of claim 15,further comprising conveying at least one of the IP data packets in thegenerated set of IP data packets.
 18. The method of claim 10, furthercomprising: receiving a bandwidth (BW) indicator in order to adjust thewireless communication device's operation bandwidth that facilitatesreception of the IP data packet at a predetermined rate, wherein saidpredetermined rate ensures a specific application queue size; generatinga BW offset in response to the received BW indicator; and generating apower indicator that conveys a power level that ensures a power spectraldensity is preserved when the operation BW is adjusted in response tothe generated BW offset and the received BW indicator.
 19. The method ofclaim 10, wherein the conveying further comprises conveying of the datapacket queue at a time of a handoff event.